code: def init_client(self, protocol, host, port, username, password):
      self.protocol = protocol
      self.host = host
      self.port = port
      self.url = f"{host}:{port}/v1"
      self.username = username
      self.password = password
      self.api_key = f"{self.username}:{self.password}"
      self.invalid_api_key = "invalid_token"
      self.vector_client = VectorClient(self.url, self.api_key)
      self.collection_client = CollectionClient(self.url, self.api_key)
      connections.connect(host=self.host, port=self.port)
  
file_path: milvus/tests/restful_client/base/testbase.py
imports: import json
  import sys
  import pytest
  import time
  from pymilvus import connections, db
  from utils.util_log import test_log
  from api.milvus import VectorClient, CollectionClient
  from utils.utils import get_data_by_payload
label_desc: Use image node_id 2 for calling the TestBase obj's underlying member method code with example usage: obj.init_client(protocol, host, port, username, password) without return types